Readers may recall claims of 1000 year residence times for CO2. This essay suggests a much shorter interval. -Anthony
Guest essay by Ari Halperin
Surplus CO2 is removed from the atmosphere by natural sinks at a rate proportional to the surplus CO2 concentration. The half-life of the surplus CO2 concentration is approximately 40 years. This is the conclusion of my research paper, published on defyccc.com today.
I am grateful to Prof. Fred Singer and Prof. William Happer for their help in writing this paper.
The correct (although approximate) formula for CO2 concentration leads to a number of conclusions of public interest:
- CO2 concentration in the atmosphere will increase much slower than has been claimed by the IPCC.
- A relatively small part of the anthropogenic CO2 in the atmosphere has been released by the US; a relatively large part of the anthropogenic CO2 has been released by China.
- If stabilizing or decreasing atmospheric CO2 content becomes desirable at some point in the future, that can be achieved by decreasing anthropogenic CO2 release at that time; no premature action is needed.
- The warming effect of anthropogenic CO2 is less than the warming effect of other gases and aerosols (according to IPCC calculations) in both the short and long term, so what are the motives behind this laser focus on CO2?
The topic of the CO2 removal rate has been discussed a number of times on WUWT (by Christopher Monckton of Brenchley, Docmartyn in comments on Dr. Lindzen’s article, Anthony Watts and others), and various opinions were expressed. Estimates of the half-life varied.
For some time, the subject was surrounded by confusion, created by sloppy definitions and evasive statements in IPCC assessment reports. There was a mix-up between the residence time of a CO2 molecule in the atmosphere and the rate of change of the surplus CO2 concentration. The residence time (~5 years) is of little interest, except as an indication of quick carbon turnaround. The true subject of interest is the rate of change of the surplus carbon concentration in the atmosphere. Another issue was the link between CO2 concentration and temperature. On the geological timescale, the rise in CO2 concentration tends to follow the temperature rise, concurring with a hypothesis that the latter causes the former. Nevertheless, such an effect is not significant on the multi-decadal scale. CO2 concentration in the atmosphere grows mostly because of anthropogenic release of CO2 through fossil fuels combustion and land use changes.
The paper’s full title is Simple Equation of Multi-Decadal Atmospheric Carbon Concentration Change. It is article-length (~5,000 words, not counting references), citable, and discoverable by search engines, including the Climate Sanity and Freedom Search. In a slight departure from a widely-used academic format, the paper contains a Summary (for busy readers). The abstract is as follows.
Surplus CO2 is removed from the atmosphere by natural sinks at rate, proportional to the surplus CO2 concentration. In other words, it undergoes exponential decay with a single decay constant. This conclusion is rigorously proven, using first principles and relatively recent observations of oceans. Historical data for CO2 concentrations and emissions from 1958–2013 are then used to calculate the half-life of the surplus concentration. This theoretically derived formula is found to be an excellent match to the historical CO2 concentrations over the measurement period. Furthermore, the “initial” CO2 concentration in the formula came out to be very close to the likely “pre-industrial” CO2 concentration. Based on the used datasets, the half-life of the surplus concentration of CO2 in the atmosphere is found to be approximately 40 years.